Can't give you a definitive answer to what you problem is but try some
injector cleaner. 10 month old gas is old. Gas will start to varnish in 3
to 4 months, the varnish deposist then cause havoc with the feul delivery
system.

Next time drain the gas, or put some stabilizer in it before leaving it for
so long. This will help.

Good luck,

Stefan


"Tim Tisdale" wrote in message
om...
I need some help on this. This year when I cranked my 94 5.7
Mercruiser, I noticed a small water leak on the front of the motor.
I'm not a mechanic but it looks like it is near the water pump. After
letting it run for a while on a water hose adapter, the temp stayed
under 150 and everything looked o.k. to take the boat out for a run on
the 4th with the family. On the lake everything seemed o.k. with power
other than when we were pulling a tube, the power seemed a little off
gunning it out of the hole. Two days later I took it out again and
this time the power was way off. The boat , a 23 foot larson 220,
won't even get on plane. It seems to miss but all of the plugs are
firing when I did a spark test. At idle it seems fine but the engine
still seems to run like its missing a bit. I'm about to check the
timing next. The Oil pressure and temperature and normal. I did have
about 5 to 10 gallons of 10 month old gas in the tank before I filled
it up with 89 octane at the pump. I checked the oil and it looked o.k.
too.

Thanks for all you help,

Tim